Is it possible to dissociate old Apple ID email completely?

Changed Apple ID but still am able to reset password from old Apple ID email if I select "Forgot Apple ID or password?" at login on Apple websites, and still able to receive mail from it. Unable to remove it at appleid.apple.com, has a question mark instead of an 'X' next to it. Does not show up in Mail app preferences for 'Accounts' or on iCloud.com in Mail settings anywhere but still says it's my 'Email Address'. Any help appreciated. Thanks.